热处理对激光增材制造TC4合金耐蚀性及室温压缩蠕变性能的影响

The increasing adoption of titanium alloy equipment in aviation, aerospace, navigation and other harsh service environments requires higher corrosion resistance and better room temperature stress creep performance of component materials. This study investigates the effect of heat treatment on the corrosion resistance and room temperature compressive creep properties of Laser based Additive Manufactured (LAM) TC4 alloy, and modify the parameters of the constitutive equation in the deceleration creep stage with the creep curve. The experimental results demonstrate that the aspect ratio of the α-lamellae markedly decreases after double stage annealing, while slightly increases with solution aging; the size of the α-lamellae slightly decreases after double stage annealing, while markedly increases with solution aging, leading to changes of the material in corrosion resistance, yield strength and critical stress. The corrosion current, the steady-state creep strain rate and the creep strain decrease by 64.92%, 46.31% and 50% respectively after solution aging of the as-deposited state. The corrosion current decreases by 26.14%, and the steady-state creep strain rate and the creep strain increase by 111.20% and 48.68% respectively after double annealing. Compared with the constitutive equation of TC4 alloy prepared by casting and forging process, the modified fitting coefficient demonstrates a higher consistency with the creep curve.